As those for increasing the sugar content of fruit, there have hitherto been a fruit sugar content-increasing solution, which is a solution prepared by dissolving at least one of brown sugar, fructose, sucrose prepared by purifying sugar, and glucose in water, and is scattered on or added to the soil before the harvesting of fruit (see, for example, refer to JP-A-2002-345340), and a fruit bag including an ethylene gas-adsorbent (see, for example, JP-A-2000-37142).